<!DOCTYPE html>
<html lang="en">
<head>
    <title>Bootstrap Example</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- <link rel="stylesheet" href="bootstrap.min.css">
    <script src="jquery.min.js"></script>
    <script src="bootstrap.min.js"></script> -->
    <link rel="stylesheet" href="//maxcdn.bootstrapcdn.bootcss.com/bootstrap/3.3.6/css/bootstrap.min.css">
    <script src="//ajax.googleapis.bootcss.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
    <script src="//maxcdn.bootstrapcdn.bootcss.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
    <style type="text/css">
        body {
            position: relative;
        }
        .affix {
            top: 20px;
        }
        div.col-sm-9 div {
            height: 250px;
            font-size: 28px;
        }
        #section1 {
            padding: 1px 20px;
            height: auto;
            color: #fff;
            background-color: #1e88e5;
        }
        #section2 {
            padding: 1px 20px;
            height: auto;
            color: #fff;
            background-color: #673ab7;
        }
        #section3 {
            padding: 1px 20px;
            height: auto;
            color: #fff;
            background-color: #ff9800;
        }
        #section41 {
            padding: 1px 20px;
            height: auto;
            color: #fff;
            background-color: #00bcd4;
        }
        #section42 {
            padding: 1px 20px;
            height: auto;
            color: #fff;
            background-color: #009688;
        }
        @media screen and (max-width: 810px) {
            #section1, #section2, #section3, #section41, #section42 {
                margin-left: 150px;
            }
        }
    </style>
</head>
<body data-spy="scroll" data-target="#myScrollspy" data-offset="20">
    <div class="container-fluid" style="background-color: #2196f3; color: #fff; height: 200px;">
        <h1>Bootstrap Affix Example</h1>
        <h3>Fixed (sticky) vertical sidenav on scroll</h3>
        <p>Scroll this page to see how the left navigation menu behaves with data-spy="affix".</p>
        <p><strong>The left menu sticks to the page when you have scrolled a specified amount of pixels.</strong></p>
    </div>
    <br>

    <div class="container">
        <div class="row">
            <nav class="col-sm-3" id="myScrollspy">
                <ul class="nav nav-pills nav-stacked" data-spy="affix" data-offset-top="205">
                    <li class="active"><a href="#section1">Section 1</a></li>
                    <li><a href="#section2">Section 2</a></li>
                    <li><a href="#section3">Section 3</a></li>
                    <li class="dropdown">
                        <a class="dropdown-toggle" data-toggle="dropdown" href="javascript:;">Section 4 <span class="caret"></span></a>
                        <ul class="dropdown-menu">
                            <li><a href="#section41">Section 4-1</a></li>
                            <li><a href="#section42">Section 4-2</a></li>
                        </ul>
                    </li>
                </ul>
            </nav>

            <div  class="col-sm-9">
                <div id="section1">
                    <h1>Section 1</h1>
                    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
                    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
                </div>
                <div id="section2">
                    <h1>Section 2</h1>
                    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
                    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
                </div>
                <div id="section3">
                    <h1>Section 3</h1>
                    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
                    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
                </div>
                <div id="section41">
                    <h1>Section 4 Submenu 1</h1>
                    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
                    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
                </div>
                <div id="section42">
                    <h1>Section 4 Submenu 2</h1>
                    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
                    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
                </div>
            </div>
        <div>
    </div>
</body>
</html>
